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, ing the calenderin PAPER PRODUCT AND rnocnss or m I w G- SAME.

No Drawing.

To all whom it may concern:

Be it known that I, JUDsoN A. D CEW, a subject of the King of GreatBrita n, and resident of the city of Montreal, in the Province of Quebecand Dominion of Canada, have invented certain new and usefulImprovements in Paper Products and Processes of Making Same, of whichthe following is a full, clear, and exact description.

This invention relates to a new paper product and a process of makingsame, the main object of the invention being to produce a paper in whichthe sizing materials are fused or molded into the paper mass in such amanner that the density of the paper is appreciably increased, therebyiving it distinctive characteristics substantially different from papersmade with ordinary sizing ingredients.

According to my process, certain new sizing ingredients are incorporatedinto the paper stock in the beating engine, and duror drying of thepaper under special conditions of temperature and pressure, theseingredients are fused into the paper mass in such a way as to greatlyimprove the quality of the paper. In the ordinary method of making awaterproof paper, rosin size is used, which is coagulated with sulfateof alumina forming aluminum resinate, but this sizing material does notmelt or fuse either on the paper machine,

driers or in the calendering of'the paper under heat and pressure. Theresult is that when a rosin size alone is used, a brittle material isformed on drying, which has no capacity for remolding itself by treatingthe paper with heat and pressure, and consequently it is impossible toalter the physical properties of the paper, since the dried resinate ofalumina becomes crushed or pulverized by calendering and will not meltunder any of the ordinary temperatures used in the drying andcalendering operations.

On the other hand, if the properties of the rosin soap are altered byblending with the rosin size to be used, certain proportions of oils,fats or waxes, and precipitating this blended material in the beatingengine with a salt of aluminum, a product is obtained which issufiiciently fusible in character when dry that under special conditionsof temperature and pressure it can be treated in calendering, so thatthe sizing material will flow as a fused mass over the paperSpecification of Letters Patent.

Patented Sept. 30, 1919.

Application filed April 15, 1918. Serial No. 228,682.

fiber, filling the interstices of the paper making it entirelywaterproof.

In carrying out my process, I use solutions of wax and rosin size, suchas described in my U. S. Patent No. 1,174,697, or solutions of oil androsin size, such as described in my U. S. patent application, Ser. No.874,881, filed November 30, 1914, and to obtain the best results, it ispreferable to use approximately 3% of the blended sizing materialcalculated on the weight of the.

and

paper stock. This amount is practically suflicient for coating over thefibers, so that when the paper is calendered at high temperatures, thefused sizing materials will so blend as to make a uniform coatingthroughout the fibers, giving a waterproof product. For specialpurposes, I may use more than 3% of the sizing material, in order tomore completely fill the interstices of the paper and give specialcapacityfor moisture and water resistance, but in a general way it maybe stated that a satisfactory paper product cannot be made with lessthan 2% of the fusible sizing material, since the properties of thepaper only become altered when there is enough of the sizing to form acontinuous coating or film over the surface of the fibers.

I have found by maldng extensive experiments that in the manufacture ofthe ordinary water-finished wrapping paper sized with a rosin size, thepaper comes to the calenders hard sized, but after the paper ismoistened and then dried between steam heated calenders, which areheated to high temperatures and which crush the paper into asemi-translucency by the high pressure, then the water resistance thatthe paper formerly had from the rosin size is almost totally destroyed,so that the paper can be easily penetrated by water. If, however, thepaper is treated in a similar manner with sizing solutions which containsufficient wax or oil to lower the melting point of the prodnot, so thatthe mixtureof wax, rosin and alumina will fuse under temperatures ofapproximately 100 to 145 C., obtainable between the heated paper machinecalenders, then the paper product becomes molded into a fibrous masscontaining a continuous coating over the fibers of a'water repellentmaterial. The fusing point of the sizing material will vary slightly,but in general, the temperature of the drying rolls must beapproximately that of steam under pressures ranging from five pounds toone hundred pounds, or slightly above the fusion temperature of thesizing mixture. Under these temperatures, an aluminum resinate alonewill not melt or fuse and in fact the ordinary aluminum resinate cannotbe fused below temperatures which will blacken and spoil the surface ofthe paper. It is obvious that during the drying process, none of thepaper can be heated to a temperature above the boiling oint of water atatmospheric pressure, whlch' is 212 F. In order, therefore, to heat thepaper to a temperature higher than this point, it must first be driedand then passed over .or between steam heated rolls, in order that thenow dried sizing material may be fused and allowed to run.

This action is preferably done under pressure, such as exists underpaper calendering rolls, so that the material may be fused and moldedinto the fiber.

The" present application is in part a continuation of matter describedin my prior applications as follows Ser. No. 856,619 filed August 13,1914.

Ser. No. 874,881 filed November 30, 1914.

Having thus described my invention, what I claim is:

1. A process of making a waterproof product, which consists inincorporatlng into the paper stock. as a sizing agent a precipitatedmixture of wax, rosin and alumina, then drying this product, and thenheating to the fusion temperature of the sizing mixture.

2. A process of making a waterproof paper product, which consists inincorporatlng into the paper stock in the beating engine a sizingmixture having a lower meltlng point than ordinary precipitated resinateof alumina, then drying the product and then heating to a temperaturehigher than the melting point of the sizing mixture.

3. A process of making a waterproof paper product, which consists inincorporating into the paper stock in the beating en- {guns as a sizingagent a precipitated mixture of'wax with rosin and alumina, then dryingthe product, and then heating to a temperature between 100 and 145 C.

4. A paper product made from paper or p-ulp fibers, and a sizingmaterial which has a lowermelting point than that of resinate of aluminaand which has become fused after the drying of the paper product.

, 5. A Waterproof paper product having no surface coating but containinga sizing material fused on to the fibers after the drying process.

6. A paper product containing a fused sizing composition, consisting ofwax with rosin and alumina incorporated into the fibers by precipitationin the beating engine.

7 A waterproof paper product made from. paper or pulp fibers, and asizing material having a melting point below that'of resinate ofalumina, said sizing material having become fused on to the paper fibersby heating the paper product to a temperature between 100 and 145 C.

8. A process which comprises incorporating with fluent paper stock, asizing composition containing rosin size and Wax, and an aluminumcompound capable of precipitating the same, making the material intopaper, drying the paper, and heating the same to a degree suflicient tomelt the rosinwax-alumina compound.

9. A process which comprises incorporating with fluent paper stock, asizing composition containing rosin size and wax, and an aluminumcompound capable of precipitating the same, making the material intopaper, drying the paper, and heating the same to a degree suflicient tomelt the rosinoil-alu nina compound by passing the same between heatedpressure rolls maintained at a temperature above 100 C., whereby themolten material spreads itself, in fluid condition, throughout the bodyof the paper. In witness whereof I have hereunto set my hand.

JUDSON A. DE CEW.

